In making composite structures by building up a stack of tapes, each tape is comprised of a layer of collimated fibers held against a metallic foil backing for holding the fibers in position during stacking. The fibers are held against the foil backing in several ways, such as by a plasma metal spray that forms a coating to hold the fibers in position. These tapes are limited in practical length, costly, and the fiber properties may be adversely affected by the matrix when applied by plasma-spraying.
Tapes have been made with organic binders holding the fibers in position and the tape consists of two metal sheets with the binder and fibers sandwiched in between. If the binder is volatile, the final bonding of the composite cannot be done until the volatile binder is all disposed of and thus the process requires much time as well as the necessary vacuum chambers and associated pumps. Further, the fibers may become misaligned between the vaporization of the binder and the application of full densification pressure.